linux-integrity.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Petr Vorel <pvorel@suse.cz>
To: "Piotr Król" <piotr.krol@3mdeb.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
	linux-integrity@vger.kernel.org,
	Ken Goldman <kgold@linux.ibm.com>
Subject: Re: TPM 2.0 Linux sysfs interface
Date: Thu, 29 Aug 2019 09:32:46 +0200	[thread overview]
Message-ID: <20190829073246.GA28007@dell5510> (raw)
In-Reply-To: <e8b2496b-7d53-f9d7-f2b7-779b87a4132a@3mdeb.com>

Hi Piotr,

...
> >> Why is this important?
> >> - there seem to be no default method to distinguish if we dealing with
> >> TPM 1.2 or 2.0 in the system. 

> > Agreed, this affects both the LTP IMA tests and ima-evm-utils package,
> > which need to support both TPM 1.2 and 2.0 for the forseeable future.
> > The LTP IMA tests check different sysfs files to determine if it is
> > TPM 1.2 or TPM 2.0 (eg. /sys/class/tpm/tpm0/device/description,
> > /sys/class/tpm/tpm0/device/pcrs and /sys/class/misc/tpm0/device/pcrs),
> > but the "description" file is not defined by all TPM 2.0's.  It
> > shouldn't be that difficult to define a single common sysfs file.

> Thank you for that use cases I will point to that during LPC discussion.
Thanks.

> Jarkko said that what he potential can cope with is:
> /sys/class/tpm/tpm0/protocol_major

> But maybe version file is also good to go, depends what it should return
> and how that information should be obtained for various TPM versions.

...
> I'm still looking into use case to provide correct examples. I'm
> thinking about edge computing devices e.g. Azure IoT Edge, AWS IoT and
> Greengrass and its ability to perform trusted boot, but do not have
> something well exercised yet.

> Definitely there is automatic validation of hardware modules which is
> time sensitive and faster access to basic functions verification, then
> more savings to manufacturer.

> For research purposes I tried couple queries on GitHub to check who use
> pcrs throughs sysfs [1][2]. Among others you can find CoreOS, Android,
> already mentioned LTP, some google projects. Quite a lot of user space
> code to be fixed. Maybe if I will have enough time I will prepare
> statistics about usage of given endpoints to quantify how those affect
> system.
BTW: codesearch.debian.net shows nothing using pcrs in whole
Debian distro [3] [4], nothing is on gitlab either.

> [1]
> https://github.com/search?q=%22%2Fsys%2Fclass%2Ftpm%2Ftpm0%2Fdevice%2Fpcrs%22&type=Code
> [2]
> https://github.com/search?q=%22%2Fsys%2Fclass%2Fmisc%2Ftpm0%2Fdevice%2Fpcrs%22&type=Code
[3] https://codesearch.debian.net/search?q=%2Fsys%2Fclass%2Ftpm%2Ftpm0%2Fdevice%2Fpcrs&literal=1
[4] https://codesearch.debian.net/search?q=%2Fsys%2Fclass%2Fmisc%2Ftpm0%2Fdevice%2Fpcrs&literal=1

Kind regards,
Petr

      reply	other threads:[~2019-08-29  7:32 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-26 23:24 TPM 2.0 Linux sysfs interface Piotr Król
2019-08-27  1:05 ` Jason Gunthorpe
2019-08-28 15:53   ` Mimi Zohar
2019-08-28 16:15     ` Jason Gunthorpe
2019-08-30 21:20       ` Tadeusz Struk
2019-09-02 19:26         ` Jason Gunthorpe
2019-09-02 21:35           ` Mimi Zohar
2019-09-03  5:55             ` Jason Gunthorpe
2019-09-03 11:49               ` Mimi Zohar
2019-09-03 13:07                 ` Jason Gunthorpe
2019-09-03 13:23                   ` Mimi Zohar
2019-09-03 16:21                     ` Jarkko Sakkinen
2019-09-03 16:23               ` Tadeusz Struk
2019-09-03 22:40                 ` Jordan Hand
2019-09-03 23:29                   ` Mimi Zohar
2019-09-04  5:58                     ` Jason Gunthorpe
2019-09-04 11:30                       ` Mimi Zohar
2019-09-04 19:43                         ` Jason Gunthorpe
2019-09-04 20:26                           ` Mimi Zohar
2019-09-06 17:53                           ` Serge E. Hallyn
2019-08-28 15:03 ` Mimi Zohar
2019-08-28 17:15   ` Petr Vorel
2019-08-28 23:22   ` Piotr Król
2019-08-29  7:32     ` Petr Vorel [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190829073246.GA28007@dell5510 \
    --to=pvorel@suse.cz \
    --cc=kgold@linux.ibm.com \
    --cc=linux-integrity@vger.kernel.org \
    --cc=piotr.krol@3mdeb.com \
    --cc=zohar@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).